1. Field of the Invention
The present invention relates to a Stirling machine which uses a heat exchanger(s) mounted in a heat engine such as Stirling-cycle equipment (a Stirling engine, a Stirling refrigerating machine, etc.), a Vuilleumier cycle machine, a Cooke-Yarbourgh cycle machine or the like, and which is applied to various industrial fields such as a food distribution industry, an environment test industry, a medical service industry, a biological industry, a semiconductor manufacturing industry, a domestic equipment industry, etc.
2. Description of the Related Art
Heat engines such as Stirling-cycle equipment (Stirling engine, Stirling refrigerating machine, etc.), a Vuilleumier cycle machine, a Cooke-Yarbourgh cycle machine, etc. have been hitherto known and disclosed in Japanese Laid-open Patent Applications No. Hei-7-293334, No. Hei-9-151792 and No. Hei-8-158939, etc.
Of these heat engines, the Stirling refrigerating machine have been particularly put on the center stage as a refrigerating machine using flon(fluorocarbon)-alternative sources which aim to avoid the recent global environmental problems, or as a compact heat engine having high performance coefficient and high energy efficiency which is usable in a wider temperature range than the conventional cooling machines, applicable to not only cold-heat using equipment such as a freezing chamber, a refrigerator, an immersion cooler, etc. for domestic use and business use, but also cold-heat using equipment in various industrial fields such as a constant-temperature liquid circulator, a low-temperature thermostat, a constant-temperature bath (thermostat), a heat shock testing apparatus, a freeze dryer, a blood/cell preserving apparatus, a cold cooler and other types of freezing/cooling apparatuses.
According to the Stirling refrigerating machine, working gas flows through a flow passage between a compression chamber (high-temperature chamber) and an expansion chamber (low-temperature chamber), and it is heat-exchanged with a cold-heat refrigerant and a heat-radiating (hot) refrigerant flowing through a cold (endothermic) heat-exchanger (low-temperature heat exchanger) and a hot (heat-radiating) heat exchanger (high-temperature heat exchanger) respectively which are disposed along the flow passage for the working gas. A shell-and-tube type heat exchanger, a plate-fin type heat exchanger, etc. have been hitherto used as the heat exchanger of the Stirling refrigerating machine.
In this specification, each of "cold heat" and "hot heat" means a kind of physical quantity associated with heat. For example, when it is described that "cold heat" is transferred to an object such as a heat exchange medium (cold-heat refrigerant) or the like, the description means that the cold-heat refrigerant is cooled. On the other hand, when it is described that "hot heat" is transferred to an object such as a heat exchange medium (hot-heat refrigerant) or the like, the description means that the hot-heat refrigerant is heated.
FIG. 1 is a front view showing a conventional shell-and-tube type heat exchanger, and FIG. 2 is a cross-sectional view taken along a line A--A of the shell-and-tube type heat exchanger shown in FIG. 1.
The conventional shell-and-tube type heat exchanger 122 shown in FIGS. 1 and 2 has an inner sleeve 123, an outer sleeve 124 and an annular flow passage 125 which is disposed between the inner sleeve 123 and the outer sleeve 124 and through which heat exchange medium such as cooling water or the like flows. Further, a number of tubes 126 through which working gas such as helium or the like for a heat engine flows are fixed through a shell 127. The shell-and-tube type heat exchanger 122 is excellent in performance, however, a long time and much labor are needed to manufacture the shell-and-tube type heat exchanger and also the manufacturing cost is high.
In order to enhance the heat exchange performance and reliability, the heat exchanger for the Stirling machine such as the Stirling refrigerating machine or the like is required to be designed so as to have a flow passage for working gas through which working gas can uniformly flow without the flow of the working gas being disturbed even partially and also fins which are uniform in thickness and designed with high precision. In addition, in order to reduce the manufacturing cost, the heat exchanger is also required to be excellent in processing and also to enable simplification of the structure of the overall Stirling machine. However, as described above, the shell-and-tube type heat exchanger needs much labor and long time in fabrication process and the manufacturing cost cannot be reduced.